The method for inscribing a waveguide into a media glass substrate generally has the steps of: relatively moving a femtosecond laser beam along a surface of the media glass substrate while maintaining the focus of the laser beam at a depth of less than the surface, wherein the waveguide has a loss of less than 0.2 dB/cm when measured at a wavelength of light signal propagating in the waveguide during normal use of the waveguide. Particularly, the method can have varying writing parameters according to whether the waveguide is single-mode or multi-mode.

An optical waveguide article includes a base layer formed from a first glass composition with a refractive index n.sub.base and a surface layer fused to the base layer and formed from a second glass composition with a refractive index n.sub.surface. A waveguide is disposed within the surface layer. n.sub.base and n.sub.surface satisfy the equation |n.sub.surface−n.sub.base|≥0.001. A method for forming an optical waveguide article includes forming a waveguide in a surface layer of a glass laminate structure including a base layer fused to the surface layer. The base layer is formed from a first glass composition with a refractive index n.sub.base. The surface layer is formed from a second glass composition with a refractive index n.sub.surface. n.sub.base and n.sub.surface satisfy the equation |n.sub.surface−n.sub.base|≥0.0001.

Provided is an optical waveguide element that prevents leaked light generated at a forking section from entering a downstream optical waveguide such as another forking section, thereby affording minimal degradation of optical characteristics. The optical waveguide is characterized in that: at least one of two fork waveguides (20a, 20b) forking from a first forking section (20) comprises a second forking section (21, 22); slab waveguides (3c-1 to 3c-3) are formed between the two fork waveguides; and between the first forking section and the second forking section, slits (41, 42) are formed that partition the slab waveguides into a first slab waveguide area (3c-1) close to the first forking section and second slab waveguide areas (3c-2, 3c-3) close to the second forking section(s).

An optical waveguide article includes a base layer formed from a first glass composition with a refractive index n.sub.base and a surface layer fused to the base layer and formed from a second glass composition with a refractive index n.sub.surface. A waveguide is disposed within the surface layer. n.sub.base and n.sub.surface satisfy the equation |n.sub.surface−n.sub.base|≥0.001. A method for forming an optical waveguide article includes forming a waveguide in a surface layer of a glass laminate structure including a base layer fused to the surface layer. The base layer is formed from a first glass composition with a refractive index n.sub.base. The surface layer is formed from a second glass composition with a refractive index n.sub.surface. n.sub.base and n.sub.surface satisfy the equation |n.sub.surface−n.sub.base|≥0.0001.

An optical-electrical substrate for providing electrical and optical connections to a photonic integrated circuit (PIC) includes a glass body with glass optical waveguides along an upper surface, and electrically conductive vias extending through a portion of the glass body from an intermediate surface to a lower surface. The intermediate surface is arranged at an elevation positioned between the upper and lower surfaces, and may optionally support redistribution layers and an electrical integrated circuit. An optical-electrical substrate may be fabricated by defining glass optical waveguides along an upper surface of a glass body, and forming electrically conductive vias through the glass body from the intermediate surface to the lower surface. A connection method includes registering a PIC with an optical-electrical substrate as described herein; heating bonding bumps arranged between the PIC and the intermediate surface; and providing optically transmissive paths between the PIC and glass optical waveguides of the substrate.

A low propagation loss and loose fabrication tolerance waveguide for a photonic integrated circuit (PIC) device may be realized by using a weak optical confinement to the optical mode, through designing a waveguide of single or double thin strips with high aspect ratio as waveguide core. To introduce a modulation functionality on this type of PIC device, a thin-film electrooptic material may be incorporated to form a hybrid phase modulating device, where a material that can be processed easily may be used as a device layer and is bonded to, or deposited with, a thin electrooptic film that may otherwise be difficult to fabricate or process. A low insertion loss, compact size and high-efficiency phase modulator on PIC device with this type of weakly confined waveguide is disclosed.

A low propagation loss and loose fabrication tolerance waveguide for a photonic integrated circuit (PIC) device may be realized by using a weak optical confinement to the optical mode, through designing a waveguide of single or double thin strips with high aspect ratio as waveguide core. To introduce a modulation functionality on this type of PIC device, a thin-film electrooptic material may be incorporated to form a hybrid phase modulating device, where a material that can be processed easily may be used as a device layer and is bonded to, or deposited with, a thin electrooptic film that may otherwise be difficult to fabricate or process. A low insertion loss, compact size and high-efficiency phase modulator on PIC device with this type of weakly confined waveguide is disclosed.

The prism coupling methods disclosed herein are directed to determining a stress characteristic of an original IOX article having a buried IOX region with a buried refractive index profile that is problematic in the sense that it prevents the original IOX article from being measured using a prism coupler system. The methods include modifying the buried IOX region of the original IOX article in a surface portion of the buried IOX region to form a modified IOX article having an unburied refractive index profile that allows the modified IOX article to be measured using a prism coupler. The methods also include measuring a mode spectrum of the modified IOX article using the prism coupler system. The methods further include determining one or more stress characteristic of the original IOX article from the mode spectrum of the modified IOX article.

The low-loss ion exchanged (IOX) waveguide disclosed herein includes a glass substrate having a top surface and comprising an alkali-aluminosilicate glass with between 3 and 15 mol % of Na.sub.2O and a concentration of Fe of 20 parts per million (ppm) or less. The glass substrate includes a buried AgNa IOX region, wherein this region and a surrounding portion of glass substrate define the IOX waveguide. The IOX waveguide has an optical loss OL0.05 dB/cm and a birefringence magnitude |B|0.001. The glass substrate with multiple IOX waveguides can be used as an optical backplane for systems having optical functionality and can find use in data center and high-performance data transmission applications.

The evanescent optical coupler is constituted by an IOX waveguide and an optical fiber. The IOX waveguide is formed in a glass substrate and has a tapered section that runs in an axial direction. The IOX waveguide supports a waveguide fundamental mode having an waveguide effective index N.sub.W0 that varies within a range N.sub.W0 as a function of the axial direction. The IOX waveguide can also support a few higher-order modes. The optical fiber supports a fiber fundamental mode having a fiber effective index N.sub.F0 that falls within the waveguide effective index range N.sub.W0 of the waveguide fundamental mode of the tapered section of the IOX waveguide. A portion of the optical fiber is interfaced with the tapered section of the IOX waveguide to define a coupling region over which evanescent optical coupling occurs between the optical fiber and the IOX waveguide.